The availability of modern communication systems through which to communicate data is a practical necessity of modem society. Communication systems are available for use to effectuate many different types of communication services in which data is communicated between sets of communication stations to effectuate desired communication services.
Existing communication systems incorporate advancements in communication technologies. And, new communication systems are made available as a result of advancements in communication technologies. Generally, advancements in communication technologies improve the efficiencies of communication of data, permit the data to be communicated at higher through-put rates, or provide better for the communication of the data in non-ideal communication conditions. Digital communication techniques, and improvements associated therewith, are amongst the communication technologies that provide such communication advantages.
A radio communication system is an exemplary type of communication system. Many modern radio communication systems employ the use of digital communication techniques. A cellular communication system is a type of radio communication system. Network infrastructures of cellular communication systems have been installed over significant portions of the populated areas of the world, and usage of cellular communication systems through which to communicate telephonically, already popular, is increasing as additional communication services are increasingly able to be effectuated by way of such systems.
The network infrastructure of an exemplary cellular communication system generally includes a plurality of spaced-apart base transceiver stations that provide for communications with mobile stations. The mobile stations form portable radio transceivers, and the base transceiver stations each define coverage areas referred to as cells. When a mobile station is positioned within the coverage area of a particular base transceiver station, the mobile station is generally capable of communicating with the base transceiver station in whose coverage area that the mobile station is positioned. The mobile station is provided with mobility and the mobile station is permitted movement between cells defined by different ones of the base transceiver stations. Communication handovers permit continued communications by the mobile station with the network infrastructure as the mobile station travels between the cells.
Analogous types of radio communication systems that exhibit certain of the characteristics of cellular communication systems have been developed and deployed. So-called micro-cellular networks, private networks, and WLANs (Wireless Local Area Networks) are representative of radio communication systems that are operable, at least in various aspects, in manners that are analogous to the operation of a cellular communication system. Wireless local area networks, for instance, are technological extensions of conventional local area networks. That is to say, conventional local area networks, such as those that form computer networks and wireless local area networks, generally provide for the communication of packet-formatted data. A mobile node that is operable in, and forms a portion of, a wireless local area network system, is analogous to, and is sometimes functionally equivalent to, the fixed nodes of a local area network. And, analogous to conventional local area networks, wireless local area networks are constructed to permit effectuation of data-intensive communication services.
Wireless local area networks are generally constructed to communicate data pursuant to an operating protocol, such as any of the IEEE 802.11(a), (b), (g), and (n) operating protocols. A commercial 2.4 GHz frequency band is allocated for WLAN communications, and an unregulated band in the 5 GHz frequency range is also usable by WLAN systems.
The mobile nodes operable in the wireless local area networks are sometimes constructed to monitor selected frequencies within the allocated frequency bands to detect for the presence of a WLAN within communication range of the mobile node. Access points, or other network elements, of the WLAN broadcast signals that are detectable by the mobile nodes, when the mobile nodes are within the coverage areas of the WLAN. The signals broadcast by the WLAN and monitored by the mobile nodes typically include an SSID (Service Set Identifier) value that identifies the WLAN that broadcasts the signal.
More than one WLAN might be installed to provide coverage over a partially, or fully, overlapping coverage area. When a mobile node is positioned at a location encompassed by more than one WLAN, the mobile node might be capable of operation to communicate with any of the more than one WLAN. A decision is made as to which of the WLANs that the mobile node shall attempt to communicate. There is generally a preference to communicate by way of a certain WLAN of the available WLANs.
The preference order of the WLANs, with respect to a particular mobile node, is location dependent. That is to say, the preference order of the WLANs, with respect to the mobile node, is dependent also upon the location at which the mobile node is positioned. The determination at the mobile node with which of the WLANs that the mobile node shall attempt to communicate is complicated as the broadcast signals broadcast by the WLANs do not identify the locations of the WLANs. Only the SSIDs are broadcast. And, the SSIDs are not necessarily unique to a particular WLAN.
For instance, a plurality of WLANs, operated by a single operator, are sometimes identified by a single SSID value. And, different ones of the WLANs operated by the operator might be located at widely disparate locations. The relative preference of a mobile node to communicate with a WLAN, identified by an SSID, might well be different, depending upon the location with which the mobile node is positioned when the communicates are to be effectuated. When the mobile node is positioned in one location, for instance, the WLAN, identified by the SSID value, might have a first level of preference. But, when the mobile node is positioned at another location, a WLAN identified by the same SSID value might well have a different level of preference associated therewith.
Therefore, a single list that identifies, in order of preference, WLANs, identified by SSID values, is an inadequate manner by which to identify through which of the WLANs that a mobile node should attempt to communicate when communications are to be effectuated.
It is in light of this background information related to communications between a mobile node and a WLAN that the significant improvements of the present invention have evolved.